Less cloning and pattern simplifications (#3216)

* Less cloning and pattern simplifications

* Revert inclusive range and remove unecessary Error:From

keychain/src/extkey_bip32.rs

@@ -382,7 +382,7 @@ impl ExtendedPrivKey {
 		passphrase: &str,
 		is_floo: bool,
 	) -> Result<ExtendedPrivKey, Error> {
-		let seed = mnemonic::to_seed(mnemonic, passphrase).map_err(|e| Error::MnemonicError(e))?;
+		let seed = mnemonic::to_seed(mnemonic, passphrase).map_err(Error::MnemonicError)?;
 		let mut hasher = BIP32GrinHasher::new(is_floo);
 		let key = ExtendedPrivKey::new_master(secp, &mut hasher, &seed)?;
 		Ok(key)
@@ -460,9 +460,7 @@ impl ExtendedPrivKey {
 		// Do SHA256 of just the ECDSA pubkey
 		let sha2_res = hasher.sha_256(&pk.public_key.serialize_vec(&secp, true)[..]);
 		// do RIPEMD160
-		let ripemd_res = hasher.ripemd_160(&sha2_res);
-		// Return
-		ripemd_res
+		hasher.ripemd_160(&sha2_res)
 	}
 
 	/// Returns the first four bytes of the identifier
@@ -567,9 +565,7 @@ impl ExtendedPubKey {
 		// Do SHA256 of just the ECDSA pubkey
 		let sha2_res = hasher.sha_256(&self.public_key.serialize_vec(secp, true)[..]);
 		// do RIPEMD160
-		let ripemd_res = hasher.ripemd_160(&sha2_res);
-		// Return
-		ripemd_res
+		hasher.ripemd_160(&sha2_res)
 	}
 
 	/// Returns the first four bytes of the identifier

keychain/src/keychain.rs

@@ -166,14 +166,14 @@ impl Keychain for ExtKeychain {
 		let keys = blind_sum
 			.positive_blinding_factors
 			.iter()
-			.filter_map(|b| b.secret_key(&self.secp).ok().clone())
+			.filter_map(|b| b.secret_key(&self.secp).ok())
 			.collect::<Vec<SecretKey>>();
 		pos_keys.extend(keys);
 
 		let keys = blind_sum
 			.negative_blinding_factors
 			.iter()
-			.filter_map(|b| b.secret_key(&self.secp).ok().clone())
+			.filter_map(|b| b.secret_key(&self.secp).ok())
 			.collect::<Vec<SecretKey>>();
 		neg_keys.extend(keys);
 
@@ -265,7 +265,7 @@ mod test {
 
 		// adding secret keys 1 and 2 to give secret key 3
 		let mut skey3 = skey1.clone();
-		let _ = skey3.add_assign(&keychain.secp, &skey2).unwrap();
+		skey3.add_assign(&keychain.secp, &skey2).unwrap();
 
 		// create commitments for secret keys 1, 2 and 3
 		// all committing to the value 0 (which is what we do for tx_kernels)
@@ -276,7 +276,7 @@ mod test {
 		// now sum commitments for keys 1 and 2
 		let sum = keychain
 			.secp
-			.commit_sum(vec![commit_1.clone(), commit_2.clone()], vec![])
+			.commit_sum(vec![commit_1, commit_2], vec![])
 			.unwrap();
 
 		// confirm the commitment for key 3 matches the sum of the commitments 1 and 2

keychain/src/mnemonic.rs

@@ -112,7 +112,7 @@ pub fn to_entropy(mnemonic: &str) -> Result<Vec<u8>, Error> {
 }
 
 /// Converts entropy to a mnemonic
-pub fn from_entropy(entropy: &Vec<u8>) -> Result<String, Error> {
+pub fn from_entropy(entropy: &[u8]) -> Result<String, Error> {
 	let sizes: [usize; 5] = [16, 20, 24, 28, 32];
 	let length = entropy.len();
 	if !sizes.contains(&length) {
@@ -124,7 +124,7 @@ pub fn from_entropy(entropy: &Vec<u8>) -> Result<String, Error> {
 
 	let mut hash = [0; 32];
 	let mut sha2sum = Sha256::default();
-	sha2sum.input(&entropy.clone());
+	sha2sum.input(entropy);
 	hash.copy_from_slice(sha2sum.result().as_slice());
 
 	let checksum = (hash[0] >> 8 - checksum_bits) & mask;
@@ -149,7 +149,7 @@ pub fn from_entropy(entropy: &Vec<u8>) -> Result<String, Error> {
 
 	let words: Vec<String> = indexes.iter().map(|x| WORDS[*x as usize].clone()).collect();
 	let mnemonic = words.join(" ");
-	Ok(mnemonic.to_owned())
+	Ok(mnemonic)
 }
 
 /// Converts a nemonic and a passphrase into a seed

keychain/src/types.rs

@@ -163,7 +163,7 @@ impl Identifier {
 		let mut p = ExtKeychainPath::from_identifier(&self);
 		if p.depth > 0 {
 			p.path[p.depth as usize - 1] = ChildNumber::from(0);
-			p.depth = p.depth - 1;
+			p.depth -= 1;
 		}
 		Identifier::from_path(&p)
 	}
@@ -176,7 +176,7 @@ impl Identifier {
 	}
 
 	pub fn to_bytes(&self) -> [u8; IDENTIFIER_SIZE] {
-		self.0.clone()
+		self.0
 	}
 
 	pub fn from_pubkey(secp: &Secp256k1, pubkey: &PublicKey) -> Identifier {
@@ -308,7 +308,7 @@ impl BlindingFactor {
 			// and secp lib checks this
 			Ok(secp::key::ZERO_KEY)
 		} else {
-			secp::key::SecretKey::from_slice(secp, &self.0).map_err(|e| Error::Secp(e))
+			secp::key::SecretKey::from_slice(secp, &self.0).map_err(Error::Secp)
 		}
 	}
 
@@ -579,7 +579,7 @@ mod test {
 		// split a key, sum the split keys and confirm the sum matches the original key
 		let mut skey_sum = split.blind_1.secret_key(&secp).unwrap();
 		let skey_2 = split.blind_2.secret_key(&secp).unwrap();
-		let _ = skey_sum.add_assign(&secp, &skey_2).unwrap();
+		skey_sum.add_assign(&secp, &skey_2).unwrap();
 		assert_eq!(skey_in, skey_sum);
 	}
 
@@ -592,7 +592,7 @@ mod test {
 		let skey_zero = ZERO_KEY;
 
 		let mut skey_out = skey_in.clone();
-		let _ = skey_out.add_assign(&secp, &skey_zero).unwrap();
+		skey_out.add_assign(&secp, &skey_zero).unwrap();
 
 		assert_eq!(skey_in, skey_out);
 	}

keychain/src/view_key.rs

@@ -123,7 +123,7 @@ impl ViewKey {
 	{
 		let (secret_key, chain_code) = self.ckd_pub_tweak(secp, hasher, i)?;
 
-		let mut public_key = self.public_key.clone();
+		let mut public_key = self.public_key;
 		public_key.add_exp_assign(secp, &secret_key)?;
 
 		let switch_public_key = match &self.switch_public_key {